1. Field of the Invention
The present invention relates to an ink jet recording head and a method of manufacturing the same. Particularly, the present invention relates to an ink jet recording head with stacked individual head members and a method of manufacturing such an ink jet recording head.
2. Description of the Background Art
FIG. 1 is a front view of a conventional ink jet recording head. An ink jet recording head having individual head members stacked is disclosed in Japanese Patent Laying Patent Laying-Open No. 4-278357, for example. As shown in FIG. 1, such an ink jet recording head is constituted by having a plurality of individual head members stacked and inclined at an angle of .theta.1 with respect to a scanning direction X of the head.
Referring to FIG. 1, an ink jet recording head 200 includes a plurality of stacked individual heads 210. Each of the plurality of individual heads 210 includes a substrate 211 formed with a plurality of individual ink paths not shown and a plurality of thin holes 212 for discharging ink from respective individual ink paths provided at the front side of substrate 211. Each individual head 210 further includes a common electrode 213 at the top surface of substrate 211 so as to cover the individual ink paths, a plurality of electrostrictive elements 214 on common electrode 213 provided at corresponding positions of respective plurality of individual ink paths, and an individual electrode not shown provided on each of the plurality of electrostrictive elements 214.
In response to a record signal corresponding to record data from the main body of a recording device not shown, voltage is applied across each individual electrode of electrostrictive element 214 and common electrode 213. The selected electrostrictive element is deformed, whereby pressure is selectively generated in an individual ink path. Thus, ink is selectively discharged from thin hole 212 for recording.
In the above-described ink jet recording head, common electrode 213 only extends to the end of each layer of the ink jet recording head. The area of common electrode 213 facing the end portion of each layer is small. It is therefore not easy to connect common electrode 213 to the electrode element of the main body side in actually mounting the ink jet recording head to the main body of the recording device.
Since the electrodes of the second layer and of the upper layers are disposed between adjacent layers, the area of common electrode 213 facing the end of each layer becomes smaller as the distance between each individual head 210 becomes shorter. Therefore, connection with an external terminal is difficult to achieve.
Also, it is necessary to arrange the individual electrode for each of the plurality of electrostrictive elements corresponding to thin hole 212 from which ink is discharged. The number of individual electrodes is great. It is therefore extremely difficult to direct all these electrodes outside the recording head for connection with the electrode of the main body of the recording device.
Since the heads inclined as shown in FIG. 1 are stacked, the recording head can be reduced in size in the lateral direction of the figure. However, this will unnecessarily increase the recording head in the vertical direction, which is not desirable from the standpoint of reducing the size of the head.
An individual ink path is formed of common electrode 213 and substrate 211 as mentioned before. Common electrode 213 is conductive whereas substrate 211 is nonconductive. This means that the materials thereof differ. It is not easy to firmly connect different types of materials. There is high possibility of the adherence intensity of the contact surface being degraded since the contact surface is brought into contact with the ink in the individual ink path.
This induces a problem that ink cannot be discharged stably. There is also a problem that the lifetime of the recording head may be reduced.